A Potent and Selective ULK1 Inhibitor Suppresses Autophagy and Sensitizes Cancer Cells to Nutrient Stress

Area of Science:

• Biochemistry
• Molecular Biology
• Cancer Research

Background:

• Autophagy, a cellular recycling process, provides cancer cells with nutrients and energy under stress, promoting tumor growth.
• Inhibiting autophagy is a potential cancer treatment strategy, with ULK1 (unc-51 like autophagy activating kinase 1) being a key target.
• Existing ULK1 inhibitors have limitations in potency, selectivity, and cellular activity.

Purpose of the Study:

• To develop and characterize novel small molecule inhibitors of ULK1.
• To evaluate the efficacy of these inhibitors in suppressing autophagy.
• To assess the therapeutic potential of ULK1 inhibition in KRAS mutant lung cancer.

Main Methods:

• Synthesis and characterization of small molecule ULK1 inhibitors ULK-100 and ULK-101.
• Assessment of inhibitor potency and selectivity compared to a published inhibitor.
• Evaluation of ULK-101's effect on autophagy induction and autophagic flux.
• Testing the sensitization of KRAS mutant lung cancer cells to nutrient stress using ULK-101.

Main Results:

• ULK-100 and ULK-101 demonstrated superior potency and selectivity compared to a known ULK1 inhibitor.
• ULK-101 effectively suppressed autophagy induction and autophagic flux across various stimuli.
• ULK-101 treatment sensitized KRAS mutant lung cancer cells to nutrient stress, indicating a role for ULK1 in cancer cell survival under stress.

Conclusions:

• ULK-100 and ULK-101 are potent and selective ULK1 inhibitors.
• ULK-101 is a valuable tool for studying autophagy in cancer and evaluating autophagy inhibition as a therapeutic approach.
• Targeting ULK1 and inhibiting autophagy may represent a viable strategy for treating KRAS mutant lung cancers.